WO2022074430A1 - Lance de post-combustion - Google Patents

Lance de post-combustion Download PDF

Info

Publication number
WO2022074430A1
WO2022074430A1 PCT/IB2020/059357 IB2020059357W WO2022074430A1 WO 2022074430 A1 WO2022074430 A1 WO 2022074430A1 IB 2020059357 W IB2020059357 W IB 2020059357W WO 2022074430 A1 WO2022074430 A1 WO 2022074430A1
Authority
WO
WIPO (PCT)
Prior art keywords
lance
oxygen
primary
ejection
anyone
Prior art date
Application number
PCT/IB2020/059357
Other languages
English (en)
Inventor
Damien WAGNER
Jean-Christophe HUBER
Hamzeh HAMADEH
Original Assignee
Arcelormittal
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Arcelormittal filed Critical Arcelormittal
Priority to PCT/IB2020/059357 priority Critical patent/WO2022074430A1/fr
Publication of WO2022074430A1 publication Critical patent/WO2022074430A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/30—Regulating or controlling the blowing
    • C21C5/305—Afterburning
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/30—Regulating or controlling the blowing
    • C21C5/32—Blowing from above
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/46—Details or accessories
    • C21C5/4606—Lances or injectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
    • F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
    • F27B3/22—Arrangements of air or gas supply devices
    • F27B3/225—Oxygen blowing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/16—Introducing a fluid jet or current into the charge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/16—Introducing a fluid jet or current into the charge
    • F27D2003/162—Introducing a fluid jet or current into the charge the fluid being an oxidant or a fuel
    • F27D2003/163—Introducing a fluid jet or current into the charge the fluid being an oxidant or a fuel the fluid being an oxidant
    • F27D2003/164—Oxygen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/16—Introducing a fluid jet or current into the charge
    • F27D2003/168—Introducing a fluid jet or current into the charge through a lance

Definitions

  • the invention is related to a lance for blowing oxygen onto a bath of molten steel, and more particularly to a lance for post-combustion in steelmaking.
  • the main starting materials are usually a mixture of liquid pig-iron and scrap.
  • the quantity of scrap which can be added depends notably on the temperature of the liquid pig iron and on the quantity of heat generated in the converter by oxidation of chemical elements. Most of it concerns the transformation of carbon into carbon monoxide CO and then into dioxide CO2. The more CO2 is formed, the more heat is created and may be transferred to bath so as to provide energy for additional scrap melting. The transformation of CO to CO2 is known as postcombustion.
  • the first one consists in having a single oxygen flow supply and then split it in a primary flux for standard decarburization and a secondary flow for enhancing post-combustion.
  • This first technology has the advantage of requiring few modifications of existing lances and for example to keep same lance diameter and weight, thus not impairing the overall support structure of the lance and reducing investment costs.
  • Disadvantage is that the secondary flow rate of oxygen being defined by the surface ratio between primary and secondary oxygen ejection means, it cannot be managed independently form the primary flow according to the process phases. Also, if oxygen supply is limited, primary oxygen flow is reduced, which impairs the decarburization process and productivity.
  • the second technology consists in having a dual flow lance, wherein primary and secondary flows of oxygen have their own supply and are independently controlled.
  • An example of a lance according to this technology is illustrated in patent US 5,681 ,526.
  • Main advantage of this technology is that primary and secondary flows of oxygen are independently controlled which allows to more accurately control the post-combustion process and thus to increase the post-combustion rate.
  • Disadvantage of this technology is that it requires an overall change on the installation and thus high investment cost.
  • the post combustion lance must be able to inject the secondary flux of oxygen so as to provide enough oxygen at the right location for the post-combustion to happen without damaging the internal refractory layer of the steelmaking vessel.
  • the lance according to the invention must allow to reach a Post combustion rate comprised between 12 and 25%. Upper limit is needed as part of energy will be transferred to the bath, but another part will be transferred to the exhaust gas, whose temperature will thus increase which could damage exhaust gas treatment system.
  • a post-combustion lance comprising a plurality of tubes which surround one another and are concentric to a central longitudinal axis of the lance Z, among this plurality of tubes being a first central tube forming a supply duct for a primary flux of oxygen, and at least one second tube surrounding said first central tube so as to form a gap for the circulation of a secondary flux of oxygen.
  • the lance further comprises a tip located at one end of the lance and provided with at least a primary oxygen ejection mean for ejection of the primary flow of oxygen, a distributor comprising at least four channels in fluid connection with the gap for the circulation of the secondary flux of oxygen of the lance, each channel being provided with at least one secondary oxygen ejection mean, said secondary oxygen ejection mean being designed so that it forms an ejection angle with the central longitudinal axis Z of the lance from 65 to 75° and said secondary oxygen ejection mean being located at a distance d above the primary oxygen ejection mean of the tip such as the ratio between the distance d and the internal diameter D of the converter is from 0,04 to 0,15.
  • the lance of the invention may also comprise the following optional characteristics considered separately or according to all possible technical combinations: - the secondary oxygen ejection mean is located at a distance d above the primary oxygen ejection mean of the tip such as the ratio between the distance d and the internal diameter D of the converter 2 is from 0,08 to 0,15.
  • the distance d is from 250mm to 750mm.
  • the distance d is from 500mm to 750mm.
  • the ejection angle p is from 65 to 70°.
  • the secondary oxygen ejection means have an exit with an oblong shape.
  • the biggest dimension of the secondary oxygen ejection means exits is from 10 to 25mm.
  • the biggest dimension of the secondary oxygen ejection means exits is from 12,5 to
  • the distributor comprises five channels
  • the number of primary oxygen ejection means is the same as the number of secondary oxygen ejection means
  • the invention is also related to a steelmaking process using a lance according to nay of the previous embodiments wherein the flow of secondary oxygen is comprised between 50 and 135 Nm3/min.
  • Figure 1 illustrates a post-combustion process in a converter
  • Figure 2 illustrates a first embodiment of a lance according to the invention
  • Figure 3 illustrates the distributor of the lance of figure 2
  • Figure 4 illustrates a second embodiment of a lance according to the invention
  • Figure 1 illustrates a converter 2 containing a bath of molten metal 20.
  • the converter is internally covered with a wall of refractories 3 and have an internal diameter D.
  • the molten metal is pig iron which needs to be decarburized to produce steel.
  • a lance 1 is inserted into the converter and blows a primary flux of oxygen
  • This double oxygen injection is performed with a post combustion lance, as the one illustrated in figure 2, according to one embodiment of the invention.
  • a lance is usually more than 20 meters long.
  • the post-combustion lance 1 according to the invention comprises a plurality of tubes which surround one another and are concentric to a central longitudinal axis of the lance Z.
  • the lance according to the invention is made of an upper part 1 A and of a lower part 1 B joined together by a distributor 17.
  • the lower part 1 B of the lance is the one closest to the bath 20 when inserted into the steelmaking vessel 2.
  • the lance is composed of a first tube 1 1 which supplies the primary flux of oxygen 21 , a second tube 12, which surrounds the main tube 11 thus forming a first annular gap 31 for the supply of cooling water within the lance 1 .
  • the lance being subjected to high temperature during the steelmaking process it needs to be constantly cooled down so as to avoid being quickly damaged.
  • Those two first tubes go along the whole length of the lance, each in a single part, which allows reducing risks of tightness issues.
  • the first tube 1 1 is preferentially made of a material allowing the passage of a flow at a speed of at least 60m/s, such as stainless steel.
  • the lance 1 then comprises a third tube 13, surrounding the second tube 12 to form a second annular gap 32 for the supply of the secondary flux of oxygen 22 necessary for the post-combustion.
  • This third tube does not extend all along the length of the lance 1 but only along the upper part 1 A.
  • This third tube is preferentially designed so that there is a ratio of 1/5 between the section of the gap for the circulation of the primary of oxygen and the section of the gap for the circulation of the secondary flux of oxygen.
  • a fourth tube 14, comprising two parts, a first part 14A, which surrounds the third tube 13 along the upper part 1 A of the lance, and a second part 14B surrounding the second tube 12 along the lower part 1 B of the lance.
  • This fourth tube 14 thus form a third annular gap 33 allowing to draw off the cooling water.
  • this first annular gap 31 may be designed for the drawn off of the cooling water from the lance 1 while the third annular gap 33 allows the entry of the water within the lance 1 .
  • the lance 1 further comprises a tip 15, closing the lower part of the lance 1 B.
  • This tip is in fluid connection with both first 31 and third annular gaps 33 so as to close the water circuit and provide circulation of water within the lance. This furthermore allows the cooling down of the tip 15 itself which is the closest part to the molten steel and thus subjected to the highest temperatures.
  • the tip is provided with at least one primary oxygen ejection mean 16 for blowing primary flow of oxygen 21 onto the bath of molten steel and allowing decarburization.
  • the tip is provided with at least four primary oxygen ejection means 16, the optimal number depending notably on the size of the ladle and thus of the circumference of the molten bath.
  • the diameter of the primary oxygen ejection means exit depends on the same parameters. In a preferred embodiment those primary oxygen ejection means 16 have an exit diameter comprised between 40 and 50mm, preferentially between 40 and 45mm.
  • these ejection means are designed so as to eject the primary flux of oxygen with an ejection angle a with the central axis Z of the lance 1 comprised between 10 and 20°, preferentially between 14 and 18°. This allows to find the good compromise between maximisation of the surface of the molten bath receiving oxygen ang keeping sufficient distance from the refractory walls to avoid damaging them.
  • the lance is designed to receive a distributor 17 making the junction between the upper 1 A and the lower part 1 B of the lance and ensuring the circulation of water between the upper 14A and the lower 14B parts of the fourth tube.
  • This distributor 17 comprises at least four channels 6 in fluid connection with the gap 32 for the circulation of the secondary flux of oxygen 22 of the lance.
  • Each channel 6 is provided with at least one secondary oxygen ejection mean for blowing the secondary flux of oxygen 22 towards the uprising gas flux. This secondary flux of oxygen will provide necessary fuel for the further combustion of CO and the release of additional energy for scrap melting.
  • Secondary oxygen ejection means 18 are located at a distance d above the primary oxygen ejection means 16 of the tip 15 such as the ratio between the distance d and the internal diameter D of the converter 2 is from 0,04 to 0,15, preferentially from 0,08 to 0,15.
  • They may be located between 250 and 750mm above the first oxygen ejection means 16 of the tip 15, preferentially between 500 and 750mm.
  • the secondary 18 ejection mean may be simple ports located at the exit of the channels 6 or nozzles inserted at the exit of the channel 6.
  • the distributor 17 is provided with the same number of secondary ejection means 18 as the number of primary ejection means 16 provided on the tip 15. Their respective exist are preferentially shifted.
  • the exit diameter of the secondary ejection mean may be comprised between 10 and 25mm.
  • the exits may have an oblong or circular shape.
  • the secondary ejection means 18 are designed so as to have an ejection angle p with a plan perpendicular to the central longitudinal axis Z of the lance comprised between 15 and 25°. This range of angles allows to avoid damaging both the lance itself, with angles inferior to 155 and the refractory wall whose temperature would increase too much with angles higher than 25°.
  • the distributor is mounted on the lance 1 so as to be able to slide of few centimetres, less than 5 cm, along the pipe 12 in order to follow the thermal expansion of the external tube 14 due to thermal constraints it is subjected to. This is done by appropriate means, such as O-rings.
  • the distributor is furthermore provided with sealing means preventing water leakage in the annular gaps supplying the oxygen flows. These sealing means are for example O-rings.
  • Figure 3 illustrates a distributor adapted for a lance according to figure 2.
  • FIG. 4 illustrates a lance 1 according to a second embodiment of the invention.
  • the layout of the different tubes forming gaps for fluid supply is different from the previous one.
  • the lance instead of having, starting from the central duct the supply of primary oxygen, water, secondary flux of oxygen and water, in this configuration the lance provides primary oxygen, secondary oxygen and inlet and outlet water.
  • Configuration of the tip 15 and of the distributor 17 are adapted to be compatible with this embodiment but all parameters of the previous embodiment, namely size, shape, angle and location of the ejection means apply to this embodiment.
  • the primary 16 and secondary 18 oxygen ejection means may be conical or parabolic nozzles.
  • flow of secondary oxygen is preferably comprised between 50 and 135 Nm 3 /min.
  • ANSYS Fluent software was used, which is a commercial finite volume solver used for CFD.
  • the model is independent of time, i.e. steady state.
  • the governing equations are conservation of mass, momentum and energy.
  • the turbulence was described by the standard k-e turbulence model.
  • Post Combustion rate is representative of the amount of CO gas which is transformed in to CO2, thus releasing energy.
  • the temperature of the refractory wall must be controlled as too high temperatures may damage them. Absorbed energy by the bath will impact the amount of scrap which can be additionally loaded into the bath. Temperature of exhaust gas must be monitored to avoid releasing gas at a too high temperature which could damage the overall exhaust gas recovery and treatment system.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)

Abstract

Une lance de post-combustion (1) comprenant une pluralité de tubes placés l'un autour de l'autre et qui sont concentriques par rapport à un axe longitudinal central de la lance Z, une pointe (15) située à une extrémité de la lance (1) et pourvue d'au moins une sortie d'oxygène principale (16) permettant l'éjection du flux principal d'oxygène (21) et un distributeur (17) comprenant au moins quatre canaux (6), chacun étant pourvu d'une sortie d'oxygène secondaire (18) et étant conçu de manière à former un angle d'éjection avec l'axe longitudinal central de la lance compris entre 65 et 75° et étant situé entre 150 et 750 mm au-dessus de la sortie d'oxygène principale (16) de la pointe (15).
PCT/IB2020/059357 2020-10-06 2020-10-06 Lance de post-combustion WO2022074430A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/IB2020/059357 WO2022074430A1 (fr) 2020-10-06 2020-10-06 Lance de post-combustion

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/IB2020/059357 WO2022074430A1 (fr) 2020-10-06 2020-10-06 Lance de post-combustion

Publications (1)

Publication Number Publication Date
WO2022074430A1 true WO2022074430A1 (fr) 2022-04-14

Family

ID=73020248

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2020/059357 WO2022074430A1 (fr) 2020-10-06 2020-10-06 Lance de post-combustion

Country Status (1)

Country Link
WO (1) WO2022074430A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024100435A1 (fr) 2022-11-10 2024-05-16 Arcelormittal Lance de post-combustion

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4971297A (en) * 1988-03-11 1990-11-20 Arbed S.A. Nozzle for refining lance
US5681526A (en) 1996-04-23 1997-10-28 Usx Corporation Method and apparatus for post-combustion of gases during the refining of molten metal
EP0874060A1 (fr) * 1997-04-25 1998-10-28 LTV Steel Company, Inc. Procédé à moussage de scories utilisant une lance à soufflage par le haut avec un circuit multiple
US5865876A (en) * 1995-06-07 1999-02-02 Ltv Steel Company, Inc. Multipurpose lance
JP2006348331A (ja) * 2005-06-14 2006-12-28 Jfe Steel Kk 溶融金属精錬用上吹きランス及び溶融金属の吹錬方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4971297A (en) * 1988-03-11 1990-11-20 Arbed S.A. Nozzle for refining lance
US5865876A (en) * 1995-06-07 1999-02-02 Ltv Steel Company, Inc. Multipurpose lance
US5681526A (en) 1996-04-23 1997-10-28 Usx Corporation Method and apparatus for post-combustion of gases during the refining of molten metal
EP0874060A1 (fr) * 1997-04-25 1998-10-28 LTV Steel Company, Inc. Procédé à moussage de scories utilisant une lance à soufflage par le haut avec un circuit multiple
JP2006348331A (ja) * 2005-06-14 2006-12-28 Jfe Steel Kk 溶融金属精錬用上吹きランス及び溶融金属の吹錬方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024100435A1 (fr) 2022-11-10 2024-05-16 Arcelormittal Lance de post-combustion

Similar Documents

Publication Publication Date Title
CN1873287B (zh) 在气流中引起涡旋
CN101078515B (zh) 改进的燃烧器屏板以及相关方法
JP4309257B2 (ja) ガス吹き込みランス
JP4789327B2 (ja) 容器内にガスを注入するための装置
BRPI0708457B1 (pt) Unidade de fusão redutora direta para produzir metal fundido a partir de um material de alimentação metalífero
CN110042199B (zh) 用于碱性氧气炉的底部搅拌风口和方法
KR102342201B1 (ko) 순산소 전로용 통풍구
US20080128963A1 (en) Apparatus for injecting gas into a vessel
KR101174678B1 (ko) 야금 공정설비
KR20010078132A (ko) 용기 내에 고체 입자 물질을 주입하기 위한 장치
WO2022074430A1 (fr) Lance de post-combustion
JP2006112779A (ja) 容器にガスを注入するための装置
US20230366052A1 (en) Lance for blowing oxygen in steelmaking
EP0644269B1 (fr) Procédé pour contrÔler la formation d'accretions à une tuyère à combustible-oxygène
BRPI0504439B1 (pt) Aparelho para injetar gás em um vaso
RU2285049C2 (ru) Устройство для подачи газа в емкость
WO2024100435A1 (fr) Lance de post-combustion
US4302244A (en) Steel conversion method
CN101280350A (zh) 用于向容器内注入物料的装置
RU2066689C1 (ru) Способ выплавки стали в конвертере
JP2001032011A (ja) 溶融金属吹錬用上吹きランス
BR112014009106B1 (pt) Lança de sopro superior e métodos para refino de ferro fundido

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20797555

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20797555

Country of ref document: EP

Kind code of ref document: A1